Context: No trials for childhood overweight have examined maintenance interventions to augment the effects of initial weight loss programs.
Objectives: To determine the short-term and long-term efficacy of 2 distinct weight maintenance approaches vs no continued treatment control following standard family-based behavioral weight loss treatment for childhood overweight, and to examine children's social functioning as a moderator of outcome.
Design, setting, and participants: A parallel-group, randomized controlled trial conducted between October 1999 and July 2004 in a university-based weight control clinic. Participants were 204 healthy 7- to 12-year-olds, 20% to 100% above median body mass index (BMI) for age and sex, with at least 1 overweight parent. Children enrolled in 5 months of weight loss treatment and 150 were randomized to 1 of 3 maintenance conditions. Follow-up assessments occurred immediately following maintenance treatments and 1 and 2 years following randomization.
Interventions: Maintenance conditions included the control group or 4 months of behavioral skills maintenance (BSM) or social facilitation maintenance (SFM) treatment.
Main outcome measures: BMI z score and percentage overweight.
Results: Children receiving either BSM or SFM maintained relative weight significantly better than children assigned to the control group from randomization to postweight maintenance (P< or =.01 for all; effect sizes d = 0.72-0.96; mean changes in BMI z scores = -0.04, -0.04, -0.05, and 0.05 for BSM alone, SFM alone, BSM and SFM together, and the control group, respectively). Active maintenance treatment efficacy relative to the control group declined during follow-up, but the effects of SFM alone (P = .03; d = 0.45; mean change in BMI z score = -0.24) and when analyzed together with BSM (P = .04; d = 0.38; mean change in BMI z score = -0.22) were significantly better than the control group (mean change in BMI z score = -0.06) when examining BMI z score outcomes from baseline to 2-year follow-up. Baseline child social problem scores moderated child relative weight change from baseline to 2-year follow-up, with low social problem children in SFM vs the control group having the best outcomes.
Conclusions: The addition of maintenance-targeted treatment improves short-term efficacy of weight loss treatment for children relative to no maintenance treatment. However, the waning of effects over follow-up, although moderated by child initial social problems, suggests the need for the bolstering of future maintenance treatments to sustain effects.
Trial registration: clinicaltrials.gov Identifier: NCT00301197.